A euphemism used by Tenacious D to refer to something that's shitty. Can be heard in the episode "Angel in Disguise".

Jack Black: Kyle took a bullet for me, now I gotta rock the three.
Kyle Gass: (as a ghost) I took a bullet for JB, now I'm in heaven and I can see.
JB: Your decision to rescue me...
KG: Was definately Poops McGee.
JB: No way, no KG I disagree.
KG: Why?
JB: Your decision to rescue me...
KG: Yeah
JB: Was the decision to set you free...
KG: (Walks onto stage) Was definately Poops McGee.
JB: Wait this is fuckin with my head. I totally thought he was dead.
KG: Just remember what you said. The medallion's made of bulletproof lead.
In harmony:
KG: I took a bullet for JB.
JB: Kyle took a bullet for me.
KG: Now I'm in Heaven and I can see.
JB: Now I got to rock for three.
KG: No no no no.
JB: KG and me.
Both: Don't forget about Tenacious D.